Continuous absorption refrigeration machine



Sept. 19, 1939. I 5 Y 2,173,294

CONTINUOUS ABSORPTION REFRIGERATION MACHINE I FiledDec. 14, 1957 FIG (9 Patented Sept. 19, 1939 UNITED STATES commons snsoamon nsrnmnaa- Tron amounts Alexander Bikkers, The Hague, Netherlands, assignor to Willem Frederik Pool, Haarlem, Netherlands Application December 14', 1937, Serial No. 119,714 In the Netherlands September 1, 1936 9Claims.

cation with the evaporator system. In this manner only'the cold contained in the refrigerant 15 is transmitted from the evaporator to the ab.-

sorber and not' the cold contained in the inert gas contained in the evaporator. Although cold conveyed from the evaporator to the absorber by circulating gas may be regained or recovered 2 to some extent by providing a heat exchanger between the relatively warm gases passing from the absorber to the evaporator and the cold gases passing from the evaporator to the absorber, it will be understood that all losses of cold never 2:; can be prevented and that the losses will be.

low only'when the amounts of gas circulated between evaporator and absorber are-small.

. It is the object of the invention-to accelerate transmission of the'refrige'rant from the evap- 30 orator'to the absorber.

It is also an object of the invention to increase the capacity of evaporators in machines of the kind referred to and thus to increase the cold producing capacity ofmachines of the kind re! 35 ferred to in general.

Furthermore it is an object of the invention to make the process ofdiilusion more complete, viz. to cause the gases passing from the evaporatorto the absorberto consistas far as possible 40 of pure refrigerant only.

Fig. 2 is an elevation with'parts in section of another embodiment of the evaporator used in the machine according to Fig. 1.

Fig. 3 is an elevation of another modification 55 of the evaporator and Fig. 4 is an elevation partly in section of another modification of the evaporator in which the inert gas as such has a higher density than the refrigerant, viz. than the mixture of inert gas and the refrigerant. 5

Referring now to Fig. l of the drawing, 2 designates the insulated wall of a cabinet, the interior space I of which is to be cooled.

Mounted outside the said cabinet 2 is a generator, boiler or gas expelling vessel 3 provided with an electric heating device 4. This heating device may be replaced by a device using other sources of heat, such as gas burners or the like. The vessel 3 contains the refrigerant absorbing substance 5.- Water or better an aqueous solution may be'chosen as the absorbent, e. g. when .arator or rectifier 6, which may be of any well known construction. In the embodiment shown it has a plurality of baiiles l by which-particles of solution carried by the flow of refrigerant vapour are separated and returned to the body of liquid 5. q

The expelled refrigerant gas thereupon passes through the condenser I in which it is liquefied by the cooling action of the outer air or of a' cooling agent, such as water.

v The refrigerant then reaches the evaporator 9 mounted within the cabinet 2.v Means are provided therein for facilitating the evaporation of the liquefied refrigerant. In Figs. 1 and 4 such means are designated by the numerals l0 and H. It will be understood, however, that sumcient evaporation could be attained by other suitable means.

The numeral i0 designates a hat plate having an upturned edge over which the refrigerant liquid flows, falling upon the plate ll having also an upturned edge. Both cascades formed in this manner suillciently agitate the refrigerant liquid to cause full evaporation.

In the embodiment according to Fig} l the I absorption machine contains as an inert auxiliary gas a relatively light gas, viz. a gas having a low density, such as hydrogen. Part of this gas enriched with refrigerant by evaporation thus will have the tendency to sink down in the evaporator. The low temperature of this part of the gas due to the evaporation of the refrigerant. also promotes its sinking movement.

The mixture rich in refrigerant thus will acorator. I

The absorber in the machine according to Fig. 1 is formed by three branches lia, lib and lie of the zigzag tube. I Absorption liquid enters the absorber through the conduit it at the top, said top lying a little underneath the level II of the liquid in the generator 3 so that the liquid freely can flow from the generator 3 through the tube l6 into the absorber. This liquid flows down within the absorber enriching itself with refrigerant and being heated to some extent by the absorption process. Thereafter it flows through the tube I! in heat exchan e relation with the liquid flowing in tube l6 and is thus further preheated and thereuponpass'es through the coil I! in close proximity to the heating element 4. This special heating of the contents of the tube It makes the latter act as a heat pump by which the liquid leaving the absorber is lifted to the level I1 01' the liquid in the generator 3.

The gas which is poor in refrigerant passes through the tube 26 following a path indicated by arrows in the drawing. It may be gathered from the drawing that a continuous circuit is formed through the absorber, the tube 26, pipe 23, member 24, pipe 26, the outer chamber of heat exchanger 30 and outlet 21. It may be necessary to start or to maintain this circulatory flow by separate means if the natural circumstances of difference in temperature and difference in density are not suflicient therefor. In general such artiilcial driving means for maintaining the said circulation will be advantageous because only in that event will the'circulation be controllable and adjustable. In thedrawing it is shown how the circulation can be driven by injection of gas under pressure taken e: g. from the high pressure part of the machine, such as the rectifier or separator 6. A small quantity of refrigerant vapour is led away from this point of high pressure through a tube 2| and injected through the nozzle 22 into the tube to support the flow of the medium in the desired direction.

The absorber gas mixture flowing through the tube 20 enters the evaporator 9 at 23, but the said gas mixture is not free to intermingle with the contents of the evaporator 9. This absorber gas, poor in refrigerant, enters a gutter-, U or similarly shaped member 24 having its openings downwards. This member is arranged near the bottom of the evaporator'space l2v in any suitable manner, e. g. extending along the walls of the evaporator 9. It ends at 25, where it communicates with the passage 26 through which the gas can reach the absorber at 21. The gutter shaped member 24 is continuous but is shown in Fig. l

l2 of the evaporator. v An effective diffusion of refrigerant therefor will occur from the evapor'ator gas mixture into the absorber gas mixture,

because the effective surface is large (the whole surface at the underside of the member 24) and the length of the path which the molecules of the rated metal sheets.

refrigerant have to traverse when passing over from one gas into the other is very short, no inactive layer of substantial thickness being between the two gases. Moreover the difference in partial pressure is maintained continuously high, as poor absorber gas is continuously supplied to the member 24 and rich evaporator gas continu-- ously sinks down to the bottom space l2 of the evaporator.

v If the difference in density between the two gases were too small to preventintermingling', it would be possible to cover the downwardly directed opening of thegutter-shaped member 24 by a wall or partition preventing intermingling of the gases but permitting diffusion of the refrigerant from one gas into the other. Such a wall or partition could be formed by porous sheets such as fabrics or by perforated sheets, such as perfo- Also grids or the like could be used and also the opening could be formed as slots. The invention is not restricted to any particular embodiment in this respect.

The absorber gas, thus enriched in refrigerant and leaving the evaporator through the passage 26, is only cooled down due to contact with the evaporator gases and due to the cold refrigerant taken up. By means of the heat exchanger 30 much of this cold is recovered so that only a very small amount of cold will be transmitted from the evaporation taking place somewhat unsymmetrically within the evaporator it will be possible to have a continuous flow ofgas rich in refrigerant established through the circulatory passage according to the arrows 3|, 32, 33. The circulatory passage referred to includes a box-like chamber 34 covered by a perforated or porous plate 35.

' At the other side of the said plate 35 another box-like chamber 36 is provided. This chamber 36 is included in the circuit of the absorber gases, thus inserted between the tubes 20, 26. At either side of the plate 35 there is thus a flow of gases which gases do not intermingle when the lighter gas is flowing above the plate 35 and when both gases flow in the same direction. There will be, however, an effective diffusion from the chamber 34 through plate 35 into the chamber 36 due to the rathergreat difference in partial pressure of the refrigerant.

In the modification shown in Fig. 3 a horzontal part of the tube 20 is arranged within a horizontal enlarged portion of the tube 26. The contents of the tube 20 are warmer than those of the tube 26 and therefore the said arrangement acts as a heat exchanger. Diffusion takes place through the plate 35.

Fig. 4 shows a modification of the evaporator which may be used if the refrigerant has a lowerdensity viz. is lighter than the inert auxiliary gas (e.'g. if nitrogen is used as an inert auxiary gas and ammonia as the refrigerant). In this event the richer evaporator gases are at tt top of the evaporator and therefore the guttershaped member 24 is arranged at a higher level than in the case of Fig. 1. Moreover the opening of the member 24 is directed upwardly, the rich evaporator gases floating on the heavier absorber gases. The process is otherwise similar to that described with reference to Fig. 1.

' is, no great difference in specific weight between. I

the rich and -the poor gas-mixture it would not 15" or partition, such as vanes or the like.

restricted-to the embodiments shown; If there be necessary e. g. to arrange the. diffusion plane, 'i. e. the geometric separation between both mixtures, horizontally In. that 'event it even could be a vertical plane on either side of which the gases new .or circulate so that these gm are not one above. the other but side by side.

provided with a conduit connecting one side of The said plane could take, however, also'an'in- .clined position or havea curved form, e. g. that of a cylinder.

Means may be provided to force the gases to flow'as. nearas possible along the diffusion plan What I clannis:'-

a continuous absorption machine containing an inert gas equalizing the diiferencesrn the" refrigerant pressure, an evaporator enclos-' i'ngaspace'Within which an inert gas carry n refrigerant circulates and an absorbercircuit 4 within which-an inert gas carrying refrigerant circulates part of the evaporator space in which L 25 :the inert gas is rich in refrigerant being infree communication with a' part of the absorber circuit inwhich the; inert gas, poor in refrigerant,

flows in a substantially horizontal direction, the communication being established along-a plane,

the inert gas carrying refrigerant having the greatest density being underneath, the-other above the said plane. l

2 continuous a s p q machine tainin'g-an inert gasequalizing the differences in the refrigerant pressure, -an evaporator enclose:

ing -a space within which an inert gascarrying refrigerant circiilates and an absorber circuit withinlwhich anj-inert gas carrying refrigerant circulates-part of the evaporator space in which the inerteas is ,richin refrigerant infree communication; with; a part of the absorber circuitin which the inert gas, poorin refrigerant, .flows in .a substantially horizontal direction, the

' taining an inert 'gas equalizing the differences in -the'refrigerant'pressure, an evaporator enclosing communication established along aplane, both gasmixture's on either side of the said plane flowing in parallel and in concurrent, directions.

3. In a continuous. absorptionmachine bon a space within which aninert gas carrying re? frigerant circulates and an, absorber circuit withinwhich "an inert gas carrying refrigerant taining' an inert gasequalizing the differences in circulates part ofthe; evaporator space in which l theinert gas is 'rich'in refrigerant being free com- "munication with. a part'of the absorber circuit which the inertgas, poor in refrigerant, flows in a substantially horizontal-direction, the -commun'ication being established along a plane, the

said plane being materialized 'by a partition -hav-; ins a p ur y iopenin s. 4. In a continuous-absorption .machine conthe refrigerant pressure,- an'evaporator enclosing a:spav:e within which an inert gas carryingre;- fri'gerant circulates and an absorber .circuit within which aninert gas-carrying refrigerant circulates-part of the evaporator space in which the inert gas is rich in refrigerant being in free communication with apart-of the absorber cit-' ithe conduit cuitrin which the inert, refrigerant flows i asubstantially horizontal direction, the

communication being established along a plane, the said plane being 'materializedby a porous. partition, permitting diffusion of the refrigerant from the evaporator space -into the absorber '5. In acontinuous absorption machine conan inert gas serving to'equalize the differenccs the refrigerant pressure, an absorber the absorber with the other side and constituting with the absorbera continuous circuit for the. inert gas carrying refrigerant to the absorber, a vaporizer comprising 'a chamber, said conduit passing through said chamber and being guttershaped and having one side open to free communication with said chamber.

6. A continuous absorption machine as defined. in claim 5 in which the inert gas'has ahigher densityrthan the refrigerant and in which the -open side ofthe gutter-shaped portion of the "conduit the chamber is disposedupwardly;

. wardly. 8. Anabsorption machine of the typeinwhich 30 density than-the refrigerant and in which the.

an inert gasis usedt'o equalize the diflerences in refrigerantpressurecomprising a vaporizer and an absorber, an external conduit connecting;opposite sides of the absorber and constituting with the absorber a continuous path forthe circula tion of. inert gas'carrying refrigerant to the abconduit traversing the vaporizer and open sorber, a substantially horizontal portion of said on oneside and closed on the other side the vaporizer, the open side. of-the conduit et- 7 the gases therein todiflfusing contact with the gases within the'vaporizer, the closed side of said conduit being disposed to prevent vertical movement of. the gases therein depending upon their density relafiveto the density of the gases inthevap'orizer. r l I V 9. In.a continuous absorption machine 'con- .tainingan inert gas serving to equalize the dif-- ferences in the refrigerant pressurein different parts of the machine, an absorber provided jwlth inlet and outlet connections for; the absorbent medium and with a conduit connecting one side latter-to pass to thesaid assembling space with- 1 out leaving the evaporator system, the said conduit contacting in a horizontal portion thereof 7 with the said assembling ace, communication .-being established in 'the contacting,areaso as to permit diffusion between the gas'mixtures in and the said assembling space i CERTIFICATE'OF CORRECTION.

S'eptember 19, 1939.

Patent No. 2,1752%. v

- I ALEXANDER B IKKERS. It is hereby certified that error appears in the printed specification of the above numbered patent requiring cbrrecticn as follows; Page 5, first column, lines 211,, 59, 5 and 62, claims 1, 2, 5andl; resp ectively after the word "circulates" insei't a comma} "line'fib, claim. ,.fp'kr bre "free" insert in; and that the saidLetters Patent shouldbe rgd with this cor-ree tion therein that the'same may'confonm to the reed rd 6f the case in the Patent Office. I

Signed and sealed this 17th day of October, A. D. 1959.

. 'Heni'y Van Arsdale (Seal) Acting Commissioner of Patents. 

